Single crystal diamond membranes for quantum networking and sensing

Atomic defects in single crystal diamond, such as nitrogen vacancy centers and silicon vacancy centers, are promising qubit candidates for quantum communication and quantum sensing applications. However, it is difficult to fully utilize their advantages in bulk diamond due to its high refractive index and limited nanofabrication methods. Therefore, to allow better integration flexibility of color centers while maintaining their coherence properties, we developed a process to create high quality, atomically smooth, large-scale single crystal diamond membranes that can be placed on any carrying wafers. Herein we will present the fabrication steps in detail, including He⁺ implantation, CVD overgrowth, electrochemical etching, flipping, transfer, and backside etching. Additionally, recent progress related to the integration of these diamond membranes will be demonstrated, namely, photonic cavity integration and creation of group IV and nitrogen vacancy defect centers, which would be beneficial in multi-qubit network, hybridized quantum systems, and quantum sensing.